CN101124467B - Micro slit viscometer with monolithically integrated pressure sensors - Google Patents
Micro slit viscometer with monolithically integrated pressure sensors Download PDFInfo
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- CN101124467B CN101124467B CN2005800148421A CN200580014842A CN101124467B CN 101124467 B CN101124467 B CN 101124467B CN 2005800148421 A CN2005800148421 A CN 2005800148421A CN 200580014842 A CN200580014842 A CN 200580014842A CN 101124467 B CN101124467 B CN 101124467B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L13/00—Devices or apparatus for measuring differences of two or more fluid pressure values
- G01L13/02—Devices or apparatus for measuring differences of two or more fluid pressure values using elastically-deformable members or pistons as sensing elements
- G01L13/025—Devices or apparatus for measuring differences of two or more fluid pressure values using elastically-deformable members or pistons as sensing elements using diaphragms
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
- G01N11/02—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material
- G01N11/04—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material through a restricted passage, e.g. tube, aperture
- G01N11/08—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material through a restricted passage, e.g. tube, aperture by measuring pressure required to produce a known flow
Abstract
An improved micro slit viscometer includes a combined micrometer depth rectangular slit flow channel with monolithically integrated multiple pressure sensors in the flow channels and a pumping system that injects a test sample to the channel at a desired flow rate. Pressure sensing diaphragm of the monolithically integrated pressure sensors is smooth to minimize the flow disturbance thereby measuring accurate local pressures. With the measurement of the pressures at various locations of the channel the true viscosity of test sample can be calculated. The viscometer may consist of multiple flow channels and thus the true viscosity at multiple shear rates can be measured simultaneously for a given flow rate thereby obtaining a full viscosity curve as a function of shear rate of non-Newtonian liquids in a much faster manner. The viscometer needs only a miniscule amount of sample, which minimizes a waste of test material. The flow channels and the monolithically integrated pressure sensors are fabricated using microfabrication processes o wafers and combined, which greatly reduce the production costs.
Description
Technical field
The invention belongs to the midget plant field of measuring the liquid true viscosity.
Background technology
Viscosity is the deformation rate that measuring of liquid flowing resistance and viscosity number depend on non-Newtonian liquid, as the author is R.B.Bird, R.C.Armstrong and O.Hassager be at Dynamicsof Polymeric Liquids (dynamics of polymeric liquid) Vol.1, described in 1987 like that.Described deformation rate is by unit (time)
-1Shear rate determine.The viscosity that records under known shear rate is " truly " viscosity.The relation curve of true viscosity and shear rate is the viscograph of presentation materials characteristic and is the important factor of considering in effective process.But in viscosity under the multiple situation is to record under indefinite test condition, and this makes can not know or calculate shear rate.Under fixed condition not, the viscosity number that measures only is " apparent ".Because true viscosity is to record under known shear rate, so true viscosity is general, and apparent viscosity is really not so.Instead, apparent viscosity depends on measuring system.For example, as general custom, when the axle in being immersed in a large amount of test(ing) liquids rotates with constant rate of speed, the moment of torsion of measurement axis.In this case, torque value only produces apparent viscosity, and this is because test condition is indefinite and do not know shear rate.Under the best circumstances, can record apparent viscosity as the rotating rate of shaft function.In fact, have only when knowing " constitutive equation " of test(ing) liquid, the speed of rotation of axle just may be relevant with shear rate.Yet " constitutive equation " of nearly all non-Newtonian liquid is not known.Therefore, for most of non-Newtonian liquids, can't under indefinite test condition, measure true viscosity.
Develop the method and the described method that only provide apparent viscosity and in manufacture process and material behavior characterization, be used to carry out quality control.Designed the multiple in-line viscometer that is used to carry out real-time viscosity measurement.Prior art patent Nos.5,317,908 (Fitzgerald etc.) and 4,878,378 (Harada) pay close attention to and measure apparent viscosity to carry out the system of technology controlling and process.Prior art patent No.6,393,898 (Hajduk etc.) have described the system of measuring multiple test(ing) liquid simultaneously.What these viscosity meters were measured is apparent viscosity.Yet, because the non-versatility that apparent viscosity is measured when needs, must be found out the apparent viscosity of the specific sample of measuring by ad hoc approach and the relation between the true viscosity separately.The basic development need true viscosity of formulation or material is measured.In addition, the design of process equipment and annex such as mould, model, extrusion molding screw etc. needs the true viscosity data of material.Yet apparent viscosity is measured and has been used to carry out short-time test as index, and this is because the measurement of apparent viscosity is simpler and easy and quicker and more economical usually.True viscosity more is difficult to obtain and only can be by several instruments: rheometer and capillary viscosimeter are measured described true viscosity.Rheometer applies accurate and known shear rate and measures true viscosity thus on test specimen.Rheometer serves many purposes and is equipped with in order to measure other character.Therefore, they are relatively more expensive usually.Usually need a large amount of samples by viscosity measurement with rheometers.In addition, rheometer not too is suitable for online application.Circular capillary viscometers is another kind of instrument, and described instrument can be measured apparent and true viscosity according to whether considering adequate compensation.Capillary viscosimeter need be along the kapillary pressure drop to determine viscosity.Because kapillary is circular, therefore only can measure the pressure at entrance and exit place.Because this restriction, unless therefore have two different kapillary correction entrance effects of different length diameter ratio by utilization, otherwise capillary viscosimeter energy measurement apparent viscosity only.Yet, utilize two kapillaries to make viscometer bulky and measurement become consuming time.Capillary viscosimeter: patent Nos.6 has been shown, 575,019 (Larson) in the prior art; 4,920,787 (Dual etc.); 4,916,678 (Johnson etc.); With 4,793,174 (Yau).Also disclosed micro-fluidic viscosity meter in the prior art: 6,681,616 (Michael Spaid etc.); 20030182991 (Michael Spaid etc.).Utilize the hold-up time of marker in the fluid passage to measure viscosity, unless test(ing) liquid is a Newtonian liquid, otherwise described viscosity is not true viscosity.
Rectangular aperture formula viscosity meter related to the present invention is used to measure true viscosity and at the Rheology in Polymer Processing (rheology in the polymer processing) of author for C.D.Han, it has been carried out fully description in 1976.In these viscosity meters, test(ing) liquid is measured the local pressure of given flow velocity lower edge runner in the internal flow of rectangular aperture runner and by the pressure transducer of configuration.With capillary viscosimeter on the contrary, inside, slit is flat so that can measure pressure in the slit by being installed in pressure transducer in the slit.The position of pressure transducer must fully be in runner inside to measure the pressure of fully developed flow.By pressure survey, can calculate the wall shear stress.When flow velocity changed, shear rate can change.By measuring the wall shear stress under the different shear rates, utilize known Weissenberg-Rabinowitsch amendment type to calculate true viscosity, this is than utilizing two independence situations capillaceous much simple under the situation of circular capillary viscometers utilizing.Yet, having only when width of flow path to be sufficiently more than under the situation of flow channel depth, these device for measuring viscosity are only simpler.These slit viscometers need the volume flow rate of pumping system with accurate control test(ing) liquid.Usually, when liquid flowed out extruder, slit viscometer was used as the annex of extruder.In practice at present, pressure transducer is installed to separately on the plate, and described plate has enough levelnesss and is undisturbed pressure with measurement.Yet well-known is that the disturbance meeting of stream influences pressure survey greatly, particularly for the viscoelasticity non-Newtonian liquid.Because any slight surfaceness due to the setting pressure sensor all may become the source of test specimen deposition, described deposition makes the long-term behaviour degradation.It is difficult to eliminate surfaceness that independent pressure transducer is installed.Therefore, measurement accuracy is impaired usually, and this depends on that independent pressure transducer is installed in the good degree in the runner.Have been found that and to overcome the problems referred to above by the whole integrated pressure sensor in the micro slit flow channels.For single slit geometry, only can change shear rate by the volume flow rate that changes pumping system control.Most of present slit viscometers are produced separately by conventional process for machining, and manufacturedly are used for relatively large sample.Therefore, these conventional slit viscometers are unsuitable for measuring the viscosity that the test specimen that can get is on a small quantity only arranged.Utilization has the micro slit flow channels of whole integrated pressure sensor may be very favourable.Micro slit viscometers allows to be used to make little manufacturing process of microchip and therefore can to make a large amount of these micro slit viscometers on single wafer.Therefore the present invention makes micro slit viscometers, and very cost is effective.
Summary of the invention
According to the present invention, by making monolithic pressure sensor arrays and making described array and little manufacturing runner combination independently guarantee that the pressure sensing zone has suitable smooth interior surface.Described smooth inner surface guarantees that slit flow is subjected to littler disturbance and records accurate local pressures and the more impossible damage that is subjected to the test material deposition of described inside surface.Described slit flow channel is configured to micro-meter scale so that carry out the sample that viscosity measurement only needs minute quantity.In addition, utilize the Micro-Electro-Mechanical system implementation little manufacturing process of batch and on wafer, make pressure transducer and runner.This batch wafer technique has been made a plurality of identical parts simultaneously and has been reduced the manufacturing cost of microviscometer thus.
The progress of little manufacturing and microcomputer processing technology makes sensitive solid state pressure sensor can realize miniaturization.This size reduction allows further to strengthen function.In addition, the technical progress of little manufacturing makes and is easier to regulate the sensitivity of pressure transducer and has improved the sensing circuit design.These improvement allow for and realize multiple purpose and regulate described microviscometer in order to measure multiple viscosity.
In a preferred embodiment of the invention, described slit viscometer comprises the stream pond and the pumping system of directed flow in a controlled manner.Described stream pond further comprises little manufacturing runner (or many runners) and the monolithic pressure sensor arrays with micron number magnitude degree of depth that is used to flow.The degree of depth of described passage or many passages preferably is in 1 micron the order of magnitude, and the length of described passage is longer than 100 microns, and width is wider than 10 microns.On wafer, make described runner with known batch process.Also on wafer or a plurality of wafer, make monolithic pressure sensor arrays.Described little manufacturing wafer with many runners is with known manner and the described little manufacturing wafer combination with a plurality of monolithic pressure sensor arrays.Described resultant wafer has a plurality of streams pond, and described stream pond further is blocked into independently single stream pond.In described slit viscometer, test(ing) liquid is subjected to pumping and flow to the other end with the end from described runner and measure along the gained pressure of described runner and fall.
A kind of method for optimizing is by known manner the derivant of wafer such as silicon (Si), gallium arsenide (GaAs), borosilicate (Pyrex 7740, promptly a kind of lachs glass of sending) or these materials to be etched with to form described runner.
A kind of manufacture method of preferred formation pressure transducer is to form a plurality of cavitys onboard so that the level and smooth surface measurements of described plate is extended on described cavity to form the end of described cavity, and described end will produce slight deformation in response to the pressure on the described smooth surface that is applied on the described cavity.Be applied to described lip-deep pressure on the described cavity with experiment with measuring liquid forming single and simple testing agency on each cavity.Described testing agency is capacitive character mechanism, piezoresistance mechanism or optical facilities.
Fundamental purpose of the present invention provides a kind of micro slit flow viscosity meter, and described viscosity meter comprises and the runner of monolithic pressure sensor arrays combination with the viscosity of measurement minute quantity sample.Thereby another object of the present invention is on the wafer shared in little manufacturing to make described runner and pressure transducer and described runner and pressure transducer combination and produces viscosity meter in a large number with the cost effective and efficient manner.
Description of drawings
Present being used to of envisioning implemented optimal mode of the present invention as shown in drawings, wherein:
Fig. 1 is the top plan view of micro slit flow cell of the present invention;
Fig. 2 is the vertical sectional view along the stream shown in Figure 1 pond of the line 2-2 intercepting of Fig. 1;
Fig. 3 is the vertical sectional view of the another kind of optional feeder connection and the outlet configuration in slit flow pond;
Fig. 4 is the top plan view of flow channel substrate;
Fig. 5 is the vertical sectional view along the flow channel substrate shown in Figure 4 of the line 5-5 intercepting of Fig. 4;
Fig. 6 shows a series of vertical sectional view that form the operation of cavity on the substrate with silicon wafer on the dielectric film;
Fig. 7 is the top plan view of monolithic pressure sensor arrays;
Fig. 8 is the vertical sectional view along the monolithic pressure sensor arrays shown in Figure 7 of the line 8-8 intercepting of micro slit flow cell shown in Figure 7;
Fig. 9 shows the amplification segmentation vertical sectional view of the single pressure sensor of cavity and film section;
Figure 10 is the top plan view of the pattern on the pressure sensor substrate of monolithic pressure sensor arrays;
Figure 11 is the vertical sectional view along the pressure sensor substrate shown in Figure 10 of the line 11-11 intercepting of Figure 10;
Figure 12 is the top plan view that connects the pattern on the pressure sensor membrane on boundary with pressure sensor substrate;
Figure 13 is the vertical sectional view along the pressure sensor membrane shown in Figure 12 of line 13-13 intercepting shown in Figure 12;
Figure 14 is the vertical sectional view of the another kind of optional design of monolithic pressure sensor arrays;
Figure 15 is the top plan view that is used for the piezoresister pattern on the silicon fiml of gaging pressure;
Figure 16 is the vertical sectional view in another kind of optional hyperchannel stream pond; With
Figure 17 is the skeleton view that comprises another embodiment of the slit rheometer with different size passage partly;
Figure 18 is the vertical sectional view along the slit rheometer shown in Figure 17 of the line 18-18 intercepting of Figure 17;
Figure 19 is the top plan view that comprises another embodiment of the slit rheometer with different size passage partly;
Figure 20 is the vertical sectional view along the slit rheometer shown in Figure 19 of the line 20-20 intercepting of Figure 19;
Figure 21 is the top plan view with slit rheometer of many passages placed side by side;
Figure 22 is the block diagram that the slit rheometer system of parallel stream pond and pump is shown;
Figure 23 is the block diagram with slit rheometer system of the single pump that is connected to two stream ponds; With
Figure 24 is the block diagram that is used for the slit rheometer system of bulk testing liquid, and described slit rheometer system has two pumps supplying with single stream pond.
Embodiment
An embodiment of micro slit flow cell of the present invention as depicted in figs. 1 and 2 and comprise outlet or the escape hole 21 and the runner therebetween 22 of the inlet of stream or import 20, stream.Runner 22 has the predetermined even degree of depth (gap) of micrometer range along passage.Channel width can be considered to one-dimensional problem rather than two-dimensional problems much larger than channel depth so that flow through passage.Width is preferably greater than 10 with the ratio of the degree of depth.The preferable width of passage is in the micron number magnitude.The preferred length of passage is at least 100 microns, has got rid of entrance area 23 and exit region 24 respectively.For the true viscosity of experiment with measuring liquid, thereby unshowned pumping system makes the stressed runner 22 that flows through micro slit flow cell with the controlled constant volume flow rate of test(ing) liquid.Because the volume that microfluid pool needs is less, therefore preferably be used for the pumping system of small size.Micro syringe pump is multiple a kind of in may pumping system.Micro syringe pump is easy to obtain and unshowned selected micro syringe pump is connected to the inlet 20 that flows the pond with known manner.Also unshowned tapping equipment or exhaust system are connected to outlet or escape hole 21 with known manner.
When test(ing) liquid is mobile in runner 22, produces pressure along the flow direction shown in the arrow 25 and fall.If fully away from the position gaging pressure of entrance area 23 and exit region 24 so that can record the constant pressure of fully developed flow falls, then the pressure petition of surrender is shown in the test(ing) liquid that flows in the runner 22 and has the stable state shear stress.For pressure drop measurement, pressure transducer is positioned at longshore current road 22 and is placed on pressure sensor cavities 26 away from the diverse location place in entrance and exit zone.Pressure transducer is measured the pressure of the working fluid in the runner 22 in the position of corresponding cavity 26.The pressure transducer that preferred longshore current road 22 is placed at least two pressure sensor cavities 26 and is associated has illustrated four this pressure sensor cavities among Fig. 1 and Fig. 2.Known is that liquid viscosity is very responsive to temperature.Therefore, be necessary on runner, to keep substantially even temperature to realize viscosity measurement accurately.In addition, the temperature of test(ing) liquid needs known.Therefore the preferred temperature of measuring the test(ing) liquid that flows through runner.Reason for this reason, the longshore current road is provided with temperature sensor cavities 28 near entrance area.If desired, the unshowned additional temp sensor cavities of Fig. 1 and Fig. 2 can be set at position near exit region with the monitoring temperature homogeneity or be provided for revising the temperature information of the viscosity measurement of acquisition.In bottom, stream pond, be provided with bonding pad 29 so that can the plain mode realization be electrically connected, for example be connected to PCB (printed circuit board (PCB)) sensing circuit based on microcontroller by wire-bonded technology or other surface mounting technique with necessity of pressure transducer, temperature sensor and other sensor that may be provided with.Can make the stream that enters inlet 20 and leave outlet 21 perpendicular to runner 22, as shown in Figure 2, or parallel with runner 22, as shown in Figure 3, this depends on required passage and pond configuration, and described stream meets the boundary and meets the boundary in exit and exhaust system in porch and pumping system.
The stream pond comprises flow channel substrate 30 and the sensor board that is formed by sensor film 31 and sensor base plate 32.Flow channel substrate 30 has cavity 33 as shown in Figure 4 and Figure 5, and when substrate and sensor board combination, described cavity has formed runner 22 as shown in Figures 2 and 3.Flow channel substrate 30 also can have inlet hole 34 that forms feeder connection 20 and the discharge oral pore 35 that forms channel outlet 21.Sensor film 31 has formed the level and smooth substantially monoblock type flowpath pressure sensing surface 36 of longshore current road 22 1 sides, and described surface is illustrated as the foot passage surface along Fig. 2 and orientation shown in Figure 3.Pressure transducer and temperature sensor preferably are integrated in the sensor board, have therefore formed the monoblock type integrated array of pressure transducer and one or more temperature sensors.Monoblock type pressure sensing surface 36 provides enough level and smooth flowpath pressure sensing surface pressure survey more accurately to be provided and to be placed on the pressure sensing surface separately and independently or the longer device of situation wherein such as the fruit pressure transducer potentially.
Fig. 6 shows the another kind of optional method that is used for forming at flow channel substrate 30 stream chamber 33.At first, have the unshowned Pyrex wafer 40 that is used as the hole of entrance and exit and be linked on the device silicon 41 of SOI (silicon on the dielectric film) wafer, silicon wafer comprises device silicon 41, the buried oxide 42 of utilizing conventional nomenclature name and handles silicon 43 on the described dielectric film.This as shown in Figure 6A.Etch away subsequently and handle silicon 43 to realize the wafer forming process of 6B.The oxide skin(coating) 42 that exposes forms certain pattern at 44 places, shown in Fig. 6 C, forms cavity 45 thereby subsequently device silicon layer 41 is etched with, shown in Fig. 6 D.Remove oxide skin(coating) subsequently so that the flow channel substrate shown in Fig. 6 E to be provided.Another kind of optional mode is to form cavity on silicon wafer by at first silicon being carried out oxidation.Oxide is made certain pattern to form etching mask.Subsequently, by known manner the silicon that exposes is etched with the formation cavity.Remove residual oxide subsequently.
Sensor board comprises pressure sensor membrane 31 and pressure sensor substrate 32.Between film 31 and substrate 32, at the interface, there is the cavity that is used for pressure sensor device and is used for temperature sensing device.Can the back side of pressure sensor membrane or below in, form cavity in pressure sensor substrate or in the two.When pressure was applied on the pressure sensing surface 36 on the cavity, the membrane portions of extending on each cavity produced biasing, and measured the amount of bias that film enters in the cavity and be applied to pressure on the pressure sensing surface on the cavity with indication.Fig. 2, Fig. 3, Fig. 8 and Fig. 9 show the back side of pressure sensor membrane 31 or below in the pressure sensor cavities 26 and the temperature sensor cavities 28 that form.Can measure the pressure transducer membrane portions of on cavity, extending by the pressure transducer of capacitance variations, resistance variations, optical path change or other type as required, shown in 48 among Fig. 9, the biasing of generation.
Fig. 9 shows capacitive pressure transducer, when the membrane portions on the pressure sensor cavities 26 48 when producing distortion under the different pressures that applies by the test(ing) liquid that on membrane portions 48, flows, described capacitive pressure transducer is measured capacitance variations.In the present embodiment, cavity 26 has two sidepieces 50 and 51, and each sidepiece 50 and 51 has the electrode 52 and 53 that is installed on it respectively.Insulation course 54 separates upper electrode 52 and pressure sensor membrane material, and lower electrode 53 is directly mounted on the pressure sensor substrate.Insulating material 55 is set on the upper surface of capacitor lower electrode 53 to prevent that electrode from producing short circuit under pressure, and distortion will cause electrode 52 otherwise contact electrode 53 thereby described pressure will make membrane portions 48 produce fully.The electric capacity of two electrodes depends on the separation of electrode and changes along with the variation of gaps between electrodes or distance that described gap or distance produce biasing along with the membrane portions on the cavity 48 and change under pressure.
Utilize little manufacturing process on wafer, to make sensor board.Can prepare pressure sensor substrate 32 by the Pyrex wafer is processed, as shown in Figure 10 and Figure 11.Chromium or titanium and platinum are by sequential aggradation and form certain pattern with formation temperature sensor 57 on the Pyrex surface.Form bottom capacitor electrodes 53 and electrical lead 58 on the resist that is certain pattern on the Pyrex by depositing metal in.Remove resist to stay the metal that is certain pattern.If desired, can before plated metal, utilize the resist that is certain pattern Pyrex to be carried out slight etching so that most of plated metal is embedded among the Pyrex as etching mask.Subsequently with oxidate on electrode for capacitors to form insulating material 55.Can carry out ultrasonic drilling machine processing to form through hole 60 to Pyrex.
For example can utilize on the dielectric film silicon wafer to make pressure sensor membrane.As in conjunction with shown in Figure 6, and referring to Fig. 6, SOI (silicon on the dielectric film) wafer comprises device silicon 41, buried oxide 42 and handles silicon 43.Silicon wafer does not comprise pyrex40 as shown in Figure 6A on the dielectric film.Silicon wafer is made in the process of sensor film on utilizing dielectric film, forms required pressure sensor cavities 26 and temperature sensor cavities 28 thereby utilize the oxide that is certain pattern as etching mask the device silicon that becomes pressure sensor membrane material 31 to be carried out etching on below film.The fresh oxide layer of removing oxide subsequently and being used to form insulating material 54 is grown on device silicon.Metal after be deposited on the oxide skin(coating) on the device silicon that is positioned at silicon on the dielectric film and be on the resist of certain pattern.Remove resist to form capacitor upper electrodes 52 and to form the electrical lead 61 that separates by insulation oxide layer 54 and device silicon 31, as shown in figure 13.
Be used to form being linked to subsequently on the Pyrex wafer that forms pressure sensor substrate of pressure sensor membrane through processing through silicon wafer on the dielectric film of processing.Utilize the eyelet mask that material is deposited on the pyrex pressure sensor substrate forming bonding pad 29 as shown in figure 11 subsequently, and form the electrical connector 62 that links to each other with lead 58 along through hole 60.Thereby the buried oxide layer of removing silicon wafer on the dielectric film of handling silicon and the formation of order removal subsequently film is subsequently finished the forming process of pressure sensor plate.
Figure 14 shows the pressure sensor cavities 64 in pressure sensor substrate 65 rather than formation in pressure sensor membrane 66.Flat basal surface (not having well portion) in pressure sensor membrane 66 is gone up formation capacitor upper electrodes 67 and electrical lead 68 and insulation course 69.In well portion 64 and on the surface of pressure sensor substrate 65, form capacitor lower electrode 70 and electrical lead 71.Insulating material 72 is deposited on the capacitor lower electrode 70.This has formed the similar pressure sensor plate of pressure sensor plate shown in the figure to the front, and produces similar operation and enter biasing in the cavity 64 to detect and to measure film 66.Difference is to form pressure sensor cavities in pressure sensor substrate rather than pressure sensor membrane, and pressure sensor membrane will have thinner thickness uniformly.Similarly, will in substrate rather than film, form temperature sensor cavities in the present embodiment.
If adopt the piezoresistivity gaging pressure, then semiconductor film (membrane portions 48 shown in Figure 9 and film 66 shown in Figure 14) is suitably mixed to form resistor 75 with known manner, as shown in figure 15, wherein film is illustrated as 76.When the film biasing enters in the cavity, measure the resistance variations of the doped resistor device 75 on the film 76 with known manner.When film produced biasing owing to pressure, the resistance of doped region changed, and measured this variation in Wheatstone bridge (Wheatstone-bridge) configuration of for example resistor.For example, in n type (100) semiconductor wafer 76 upper edges＜110〉direction formation p type piezoresisters, as shown in figure 15.These conventional piezoresistance silicon sensors are not suitable for the high temperature that is higher than 120 ℃ and use.Be higher than in temperature under 120 ℃ the situation, p-n junction can leakage current.In order to prevent that electric current from leaking and increasing the operating temperature of these conventional piezoresistance silicon sensors, can be by insulator being placed between the p-n junction or utilizing SOI (silicon on the dielectric film) to isolate p-n junction with known manner.Another kind of optional mode is that membrane material can adopt wide bandgap material such as GaAs or SiC.
After making pressure sensor plate and flow channel substrate as mentioned above, the wafer of the wafer of the formation pressure sensor plate of combination and formation flow channel substrate connects with known manner subsequently and links together to form as Fig. 1, Fig. 2 and the wafer with complete microfluid pool shown in Figure 3, and described mode depends on pressure sensor plate and the selected combination of materials of flow channel substrate.Linking method can be glass sintering, hot compression, eutectic binding, anode binding or other method.Utilize little manufacturing process as described as an example those technologies, can make a plurality of streams pond on single resultant wafer, and can make a plurality of this wafers in batches, described manufacturing all is unusual cost effective and efficient manner.Owing to can make a plurality of streams pond on each wafer, the resultant wafer that therefore forms completed flow cells can be carried out the parts that piecemeal is divided into single stream pond with Jiang Liuchi or is divided into the single stream pond that comprises requirement.
Another kind of optional mode is, the wafer with flow channel substrate at first with dielectric film on silicon wafer link.Order is removed and is handled silicon and oxide subsequently.The device Si wafer that exposes is processed to form a plurality of sensor films.Pyrex 7740 wafers with polylith pressure sensor substrate are subjected to independent processing.Preferably link two wafers of process combination subsequently by anode.After suitably processing through hole, the wafer of binding subsequently by piecemeal to obtain single viscosity sensor.
Each stream Chi Haike comprises many runners of series connection, and described runner has the width of variation or the gap of variation, as shown in figure 16.Figure 16 shows the gap 80 of two different sizes with series connection in the particular configuration in stream as herein described pond and 81 runner.Pressure sensor cavities 82 is configured to allow to detect the hydrodynamic pressure that flows in the channel part with gap 80, and pressure sensor cavities 83 is configured to allow to detect the hydrodynamic pressure that flows in the channel part with gap 81.Temperature sensor cavities 84 allows partly to locate to carry out temperature survey and temperature sensor cavities 85 allows partly to locate to carry out temperature survey in the beginning of the channel part with gap 81 in the beginning of the channel part with gap 80.For example also can additional temperature sensor location be set at the endpiece place of channel part with gap 81.Utilize and described identical manufacturing technology formation passage and the pressure sensing plate of manufacturing technology that is used for the embodiment with constant volume passage of front, but on etching, machine work and/or other channel formation step, produce modification has two or more different gap or width with formation passage.To after content described herein is studied so far, this modification is conspicuous for the technician in employed manufacturing technology field.Figure 17-Figure 20 shows more general slit rheometer of the present invention, and described rheometer comprises the runner of the two or more various flows volumes with arranged in series.
Figure 17 and Figure 18 show the slit rheometer of the present invention with rheometer body, and described rheometer body is configured has bottom 120 and top 121.Bottom 120 has at least two recesses, there is shown three recesses 122,123 and 124, and described recess has the degree of depth h and the fixed width of variation as shown in figure 18.Recess has formed the passage of flow of liquid.Top 121 is pressure sensor plate of the present invention and the array that comprises pressure transducer 125 as shown in figure 17, described pressure transducer is illustrated as cavity 126 in Figure 18, and is spaced so that at least two sensors 125 are configured at least two diverse location place gaging pressures in each recess 122,123 and 124.Each recess has sufficient length to guarantee forming fully developed flow at each partial interior.Sensor is placed to measure the pressure of fully developed flow.Pressure sensor substrate 121 shown in Figure 18 the best has the orientation with opposite orientation shown in Figure 16.That be known as pressure sensor membrane is wafer 121a, described wafer is orientated to form the bottom of pressure sensor plate, the surface measurements of described pressure sensor plate faces down towards flow channel for liquids, and that be known as pressure sensor substrate is 121b, and described 121b is orientated to form the top of pressure sensor plate.Obviously, can use pressure sensor plate of the present invention along any orientation.
Figure 19 and Figure 20 show and are configured the slit rheometer with bottom 130 and top 131.The bottom has at least two recesses, there is shown three recesses 132,133 and 134, and described recess has the width w and the constant depth of variation.Recess has formed the passage of flow of liquid.Top 131 is pressure sensor plate of the present invention and the array that comprises pressure transducer 135 as shown in figure 19, described pressure transducer is illustrated as well portion 136 in Figure 20, and is spaced so that at least two sensors 135 are configured at least two diverse location place gaging pressures in each recess 132,133 and 134.Each recess has sufficient length to guarantee forming fully developed flow at each partial interior.Sensor is placed to measure the pressure of fully developed flow.Passage is configured so that the ratio in every width of channel w and gap is sufficiently more than 10 in all passages.
For shown in each slit rheometer for, in use, utilize to cause test(ing) liquid stream to form flow of liquid by the device of the stream that forms by the recess in the slit rheometer.This device can be other source of pump or pressurized tests liquid.In the liquid flow process, by each sensor measurement by liquid at pressure transducer position applied pressure, and can known manner determine apparent viscosity and true viscosity by this measurement.
The orientation of the bigger and littler stream that forms by the recess of different size as Figure 17 and shown in Figure 19 be opposite.Which kind of mode is flow of liquid take by slit or runner did not influence.The measured critical flow character that is used for definite apparent viscosity is two pressure differentials that sensor arrives of specific dimensions recess.Measurement result in the contrast different size recess is to determine the reality or the true viscosity of liquid.Although the recess of two different sizes will be indicated practical viscosity quite exactly, the recess that exists is many more, and accuracy is high more.The existence of two or more recesses also makes by one-shot measurement with regard to the viscosity under a plurality of shear rates of energy measurement.Yet the increase of accuracy has been offset in the expense increase that more recesses cause.For the integrated recess of slit rheometer of the present invention, the prior art that the cost of the recess of increase and use have an autonomous device in different size slit is compared and has been reduced, but the increase of recess still makes cost increase.Usually can obtain to be in excellent accuracy in the common required scope by two or three recesses.
For true viscosity is measured, replace runner to comprise the situation of at least two parts of series connection with various flows volume, each stream pond can have parallel two or many runners as shown in figure 21.Figure 21 shows two parallel stream ponds 140 and 141.Can be by the wafer that flows the pond carries out piecemeal forms this stream pond so that the parts of piecemeal comprise two or more parallel ponds to comprising.Under the situation of using two or more streams pond, can use independently pump for each different pond.This situation such as Figure 22 schematically illustrate.Pump 145 arrives the test(ing) liquid pumping in pond 147 by conduit 146.Pump 148 arrives the test(ing) liquid pumping in pond 150 by conduit 149.If the passage in pond has same size and use identical test fluid in each pond, then can with a speed fluid pumping be measured true viscosity with the fluid pumping by pond 150 with different speed by stream pond 147 and operate pump 148 by operate pump 145.The pressure measurements that obtains from each pond is compared to obtain and to be associated to obtain true viscosity with flow velocity.Certainly, if only use a pump and a stream pond, if the flow velocity of scalable pump, then test(ing) liquid can pump with the situation of an operated in flow rate under by the pond, and can change flow velocity subsequently and can carry out pressure survey for the identical test liquid that is pumped through the pond with different rates.If use a pump, then can utilize valve or a plurality of valve that stream is guided to a pond or another pond.This as shown in figure 23.Pump 152 is connected to pond 156 and 157 by divider 153 and conduit 154 and 155 respectively.The stream in pond 156 is led in valve 158 controls in the conduit 154, and the stream in pond 157 is led in valve 159 controls in the conduit 155.If the runner in stream pond has different size, then can measure true viscosity by switching at constant flow rate lower-pilot pump and between Liu Chi.Have the situation of same size for the runner in the pond,, then can measure true viscosity if flow through two ponds 156 and 157 with controlled given rate simultaneously so that come the stream of self-pumping to incite somebody to action by flow-controlled device alternative valve 158 and 159.Another kind of optional mode is, the passage that parallel stream pond can be suitably links to each other and is connected in series with formation with runner or conduit or other coupling arrangement.Therefore, the escape hole 142 of passage 141 can be connected to the import 143 of the passage 140 shown in Figure 21.This passage that is connected in series can have different channel sizes so that in fact produced the channels in series with different size or flow volume.
In some cases, desirable is the viscosity of measuring liquid mixture.In this case, can be every kind of liquid that will mix independently pump is provided, pump 160 and 161 as shown in figure 24, and be connected so that mix in the conduit 164 that mixing material is guided to pond 165 from the liquid of each pump from the output duct 162 and 163 of each pump.Control the ratio of blending ingredients by controlling two pumps 160 and 161 relative pump rate.
Should be appreciated that in measuring the process of viscosity, the constant flow rate by passage is important.Therefore, the described multiple conduit that pump is connected to runner or connects many runners should have enough rigidity to prevent to produce the stretching and the bulging that may cause the flow of liquid by passage to change.
Invention described in Fig. 1, Fig. 7, Figure 10, Figure 15 and Figure 16 have be positioned at pressure sensor substrate bottom place bonding pad so that bonding pad is connected to testing circuit.Yet, for some application, may not need this bond pad configuration.But bonding pad can be placed on the top of pressure sensor substrate and exceed runner to expose described bonding pad.The pad utilization lead-in wire that exposes is further linked to testing circuit.In order to form this bond pad configuration, should suitably be sent to bonding pad on the pressure sensor substrate top at the conductor that produces on the pressure sensor membrane.
This viscosity sensor can further be integrated with flow sensor.Flow sensor is measured the flow velocity of liquid and the pressure in viscosity sensor measurement longshore current road falls.Fall under the known situation at flow velocity and pressure, can measure apparent viscosity.In order to measure true viscosity, the pressure that needs to measure different in flow rate falls.This can have the runner of different gap or realize by changing flow velocity by connection.When liquid flow when the runner, the flow velocity in every passage is owing to the variation of xsect changes.The pressure that the variation of flow velocity has changed in every passage falls.Pressure by every measured passage falls, and can obtain true viscosity.The flow sensor that can use with viscosity sensor is hot line flow sensor, sound wave flow sensor, Coriolis flow sensor etc.These sensors are configured and integrate with known manner.
Although as the embodiments of the invention of implementing optimal mode of the present invention in practice the present invention is illustrated and illustrates in conjunction with anticipation at present at this, but be to be appreciated that, can make multiple variation so that the present invention is suitable for different embodiment, and can not depart from invention theory disclosed here.
Claims (8)
1. slit rheometer that is used for determining liquid viscosity, described slit rheometer comprises:
The integral sensor plate, it is combined to form by pressure sensor membrane and pressure sensor substrate, this integral sensor plate has at least two cavitys, these at least two cavitys are formed in pressure sensor membrane or the pressure sensor substrate, or be formed in pressure sensor membrane and the pressure sensor substrate, the part of pressure sensor membrane is extended at least on the respective cavities of these two cavitys, rely on thus to the part of on described respective cavities, extending of pressure sensor membrane and exert pressure, this part of pressure sensor membrane will be setovered and be entered in this respective cavities, the amount of bias indication is applied to the pressure on the pressure sensing surface that is on the cavity, in each of a plurality of cavitys, form pressure transducer so that the plate of the integral sensor with basic smooth surface to be provided, in this integral sensor plate, have a plurality of pressure transducers;
Channel substrate, it is configured to form single flow channel for liquids within it when making up with the integral sensor plate, this single flow channel for liquids has identical cross sectional dimensions between flow channel for liquids inlet and flow channel for liquids outlet, described runner has the width and the degree of depth, greatly at least about 10 times, and the degree of depth is in the micron number magnitude to the width of runner than the degree of depth of runner; And
Have at least two individual pressure sensors in the described single runner, these at least two individual pressure sensors fully export away from described flow channel for liquids inlet and flow channel for liquids, and the measurable flow pressure of crossing the fully developed flow of runner falls thus.
2. slit rheometer according to claim 1 additionally comprises making the stressed device that flows through runner with known volume flow rate of liquid.
3. slit rheometer according to claim 2, it is characterized in that: forcing liquid is pump with the device that known volume flow rate flows through runner, this pump has the outlet that enters the mouth into the stream connection with flow channel for liquids, this pump passes through runner with known volume flow velocity pumping liquid, the pressure of the fully developed flow that flows through runner that records falls with the known volume flow velocity of the liquid that flows through runner and combines, and the apparent viscosity information necessary of calculating the liquid that flows through this runner is provided.
4. slit rheometer according to claim 3 is characterized in that: the known volume flow velocity that is produced by pump is adjustable.
5. slit rheometer according to claim 1, wherein: described sensor board has at least one temperature sensor, and the temperature of the liquid of this flow channel for liquids is flow through in measurement that described temperature sensor is provided in flow of liquid when crossing flow channel for liquids.
6. method of making slit rheometer, described method comprises:
Form a plurality of channel cavity in channel substrate, each channel cavity has identical cross sectional dimensions, and has along the length opening on the connection surface of channel substrate;
Form a plurality of cavitys in one of pressure sensor membrane and pressure sensor substrate or both, the number of cavities of these a plurality of cavitys is formed in the twice at least of the channel cavity number in the channel substrate;
Sensor film and sensor base plate are combined to form pressure sensor plate, and the part of the pressure sensor membrane of this pressure sensor plate is extended on the respective cavities of described a plurality of cavitys;
In described a plurality of cavitys, form pressure transducer;
Connection surface along channel substrate combines pressure sensor plate and channel substrate, with the described a plurality of channel cavity of closure along the connection surface of channel substrate, to form a plurality of runners, each runner has inflow entrance and the flow export that liquid can flow through, each runner passes through from least two pressure transducers of a plurality of pressure transducers of being arranged in pressure sensor plate, these at least two pressure transducers separate along the length of each runner, and fully away from inflow entrance and flow export, the measurable flow pressure of crossing the fully developed flow of each runner falls thus, greatly at least about 10 times, and the degree of depth is in the micron number magnitude to the width of runner than the degree of depth of runner; With
The corresponding runner of a plurality of runners is divided into a plurality of independent runner that comprises a plurality of discrete gap rheometers.
7. the method for manufacturing slit rheometer according to claim 6, it is characterized in that: each channel cavity has the opposite end, inflow entrance extends through the end of channel substrate to this channel cavity, and flow export extends through the relative end of channel substrate to this channel cavity.
8. the method for manufacturing slit rheometer according to claim 7, it is characterized in that: each of described a plurality of channel cavity comprises three conduit walls, when integral sensor plate and channel substrate were combined to form described a plurality of runner, this integral sensor plate formed each the 4th wall of described a plurality of channel cavity.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US55228904P | 2004-03-11 | 2004-03-11 | |
| US60/552,289 | 2004-03-11 | ||
| PCT/US2005/007869 WO2005086883A2 (en) | 2004-03-11 | 2005-03-11 | Micro slit viscometer with monolithically integrated pressure sesonrs |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101124467A CN101124467A (en) | 2008-02-13 |
| CN101124467B true CN101124467B (en) | 2011-04-20 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2005800148421A Active CN101124467B (en) | 2004-03-11 | 2005-03-11 | Micro slit viscometer with monolithically integrated pressure sensors |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP1754036B1 (en) |
| JP (1) | JP4825791B2 (en) |
| CN (1) | CN101124467B (en) |
| WO (1) | WO2005086883A2 (en) |
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|---|---|---|---|---|
| RU2690094C1 (en) * | 2016-02-02 | 2019-05-30 | Ляйстритц Экструзионстехник Гмбх | Rheometer |
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| DE102006029285B4 (en) * | 2006-06-23 | 2008-03-13 | Technische Universität Dresden | Sensor for measuring the viscosity of a liquid |
| FR2907226B1 (en) * | 2006-10-13 | 2008-12-12 | Rhodia Recherches & Tech | FLUID ANALYSIS DEVICE, DEVICE FOR DETERMINING CHARACTERISTICS OF A FLUID COMPRISING THE ANALYSIS DEVICE, METHODS FOR CARRYING OUT THE METHOD, AND CORRESPONDING SCREENING METHOD |
| JP4845047B2 (en) * | 2007-08-31 | 2011-12-28 | 独立行政法人産業技術総合研究所 | Viscometer |
| US7784330B2 (en) * | 2007-10-05 | 2010-08-31 | Schlumberger Technology Corporation | Viscosity measurement |
| US8677818B2 (en) | 2009-03-10 | 2014-03-25 | Sensortechnics GmbH | Flow sensing device and packaging thereof |
| EP2564181B1 (en) | 2010-04-26 | 2021-08-25 | RheoSense, Inc. | Portable viscometer |
| CA2838771A1 (en) * | 2011-06-22 | 2012-12-27 | Danmarks Tekniske Universitet | A flow measurement device and method |
| KR101338171B1 (en) * | 2012-08-29 | 2013-12-06 | 인하대학교 산학협력단 | Flow control module using micro pumps and sensors |
| WO2014094791A1 (en) * | 2012-12-20 | 2014-06-26 | Danmarks Tekniske Universitet | Fluid composition analysis device and method |
| JP5992880B2 (en) * | 2013-08-26 | 2016-09-14 | 日本電信電話株式会社 | Flow cell |
| EP3155399B1 (en) * | 2014-04-11 | 2020-12-02 | Rheosense Inc. | Viscometer and methods for using the same |
| JP6762009B2 (en) * | 2016-08-16 | 2020-09-30 | 国立大学法人九州工業大学 | Body fluid viscosity measuring device |
| US11536640B2 (en) * | 2017-12-15 | 2022-12-27 | Ams International Ag | Integrated particulate matter sensor systems |
| JP6759372B2 (en) * | 2019-01-21 | 2020-09-23 | キユーピー株式会社 | Methods and equipment for obtaining rheological characteristic values of non-Newtonian fluids |
| CN109932283B (en) * | 2019-04-19 | 2021-07-27 | 常州大学 | Device and method for measuring apparent viscosity of non-Newtonian fluid at high shear rate |
| CN113188705B (en) * | 2021-04-30 | 2022-11-25 | 华力创科学(深圳)有限公司 | Small force sensor based on light path blocking method and six-axis force sensor |
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Also Published As
| Publication number | Publication date |
|---|---|
| CN101124467A (en) | 2008-02-13 |
| JP2007528501A (en) | 2007-10-11 |
| EP1754036A2 (en) | 2007-02-21 |
| EP1754036A4 (en) | 2008-12-31 |
| WO2005086883A3 (en) | 2006-11-23 |
| EP1754036B1 (en) | 2022-02-16 |
| JP4825791B2 (en) | 2011-11-30 |
| WO2005086883A2 (en) | 2005-09-22 |
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